1. Field of the Invention
The present invention relates generally to surgical implements for gripping tissue, and more particularly to forceps used in conducting vasectomies and surgical interventions in the lower esophagus or stomach.
2. Description of the Prior Art
Voluntary surgical contraception, also called contraceptive sterilization, has become the most widely used method of family planning in the world. It is also one of the safest and most economical contraceptive methods. The health benefits of contraceptive sterilization are especially evident in developing countries where temporary contraceptive methods may be periodically in short supply or used ineffectively, and where unwanted pregnancies carry a high risk of maternal death. Contraceptive sterilization may be performed on either the female (tubal ligation), or the male (vasectomy). Although both procedures are equally effective as contraceptive methods, vasectomy is simpler, safer, and less expensive than tubal ligation.
Vasectomies can be accomplished by cutting or clipping the vas deferens. Because of the relatively high failure rate of the clipping method, cutting is preferred. In the cutting method, a forceps is used during the vasectomy procedure to grasp and elevate the vas deferens, the duct which transports sperm and semen from the testicles to the penis. The vas deferens is elevated and exposed so that it may be cut and ligated, thus completely preventing the flow of sperm in the vasectomized male. In a standard vasectomy, the vas deferens is isolated, the grasping tips of forceps are clamped behind it, and the duct is elevated. Once having elevated the vas deferens, the surgeon rotates it, thus exposing its surrounding sheath, which is then dissected to uncover the duct.
A commonly used instrument in performing vasectomy is a standard forceps, such as Allis forceps. The standard forceps used in vasectomy comprises a scissors-like construction that includes a locking mechanism for the two arms at the handle end. The grasping tips, at the ends of the arms opposite the handles, have mating sawtooth extensions, which meet in a line perpendicular to the lengthwise extension of the instrument.
Because of the large area defined by the tips of standard forceps, additional tissue is often grasped and elevated along with the vas deferens. The large end structure defined by the standard forceps also frequently permits the vas deferens to escape the surgeon's grasp as he pulls it up and out of the incision. Finally, due to the large open area defined by the closed ends of the grasping tips and the pivot point of the two arms, the vas deferens often slips out of the grasp of the instrument when the duct is rotated to expose the surrounding sheath. In each case, the surgeon is required to recapture the duct, and recommence this part of the procedure. Such imprecision and slippage renders the procedure longer, and more difficult to conduct than if a forceps with a design more specific to the procedure were used.
Several attempts have been made to overcome the problems associated with the use of standard forceps in procedures requiring manipulation of ducts such as the vas deferens. U.S. Pat. No. 2,397,823, issued to Carl W. Walter, on Apr. 2, 1946, discloses a forceps intended to be capable of grasping a wide variety of objects. This forceps has a elongated "pistol-grip" handle. It is oriented at an angle of at least 45 degrees relative to a gripping portion of the device. Consequently, minute manipulations of tissue during a surgical procedure would be cumbersome at best, and dangerous at worst.
Moreover, the forceps is shown to have serrations on the very tip. Such serrations, while providing additional gripping friction, would necessarily cause destruction of surrounding tissue. Also, the presence of these serrations clearly indicate that this forceps has a clamping hole substantially recessed from the end of the device, in stark contrast with applicant's own invention. Use of such a device in a vasectomy procedure would:
require an extraordinarily large incision in the scrotum for insertion of the device, leading to increased likelihood of infection;
cause tissue damage while the device is passed into the scrotum sufficiently far for the clamping hole to engage the vas deferens;
cause tissue damage when the device is closed and clamped around the vas deferens, because tissue behind the vas deferens would necessarily be clamped in addition;
make the vasectomy procedure's lifting and turning of the vas deferens impossible without substantial destruction of surrounding tissue, because of additional tissue caught in the large extension of the forceps' tips beyond the clamping hole; and,
result in additional, unwarranted procedure length, trauma, and danger.
This device also fails to have a beveled rim around the edge of the hole nearer its grasping end to provide effective gripping for rotation of a vas deferens or other tubular tissue. Instead, it has "arcs of different curvature" disposed around the rims of recesses in the jaws, which are described as including an "almost blade-like inner edge." Such bladed arcs would tend to cut tissue held, making holding of tissue impractical. In fact, the forceps is intended for use with objects other than tissue, such as needles and swabs. Importantly, the literature describing the use of this device does not even mention use for vasectomies.
U.S. Pat. No. 2,642,871, issued to Joseph Theurig, on Jun. 23, 1953, discloses a forceps suitable for grasping tubular objects, such as syringes. The forceps has a clamping aperture described and depicted as comprising "transverse inverted obtuse angular meeting faces." The difficulty concomitant of using such a device in a vasectomy procedure is substantial. Because the aperture is not curved to the shape of a tubular duct, the vas deferens would tend to slide around within the aperture, if the device were sufficiently large to allow full closure with the tips actually contacting one another. Such sliding would make performance of the procedure impossible because the appropriate cutting and knotting of the duct would be unfeasible. Making the device smaller, so that the device would immovably hold the vas deferens, would result in failure of the device to close completely, as shown in FIG. 4 of the Theurig patent. Without complete closure, the device would tend to allow undesired release of the vas deferens during the required lifting and twisting of the vas deferens.
The Theurig forceps also lacks a beveled rim around the edge of the hole nearer its grasping end to provide effective gripping for rotation of a vas deferens or other tubular tissue. Notably, the literature referring to the use of this device does not even mention use for vasectomies.
U.S. Pat. No. 5,067,958, issued to Jeffrey J. Sandhaus, on Nov. 26, 1991, demonstrates a complicated apparatus intended to be used in procedures for implanting locking clips for clamping and occluding tubular vessels, such as the vas deferens during a vasectomy. In addition to the ancillary concerns about cost, ease of construction and maintenance, this device has several practical shortcomings in regard to use and teaching in relation to vasectomy forceps and vasectomy procedures. One problem is that it relies on clamping of the vas deferens, rather than cutting it; consequently, the desired sterilization cannot be completely ensured by the use of this device. Another problem is that its complicated operation requires special training for use, and requires additional pre-surgical preparation time. A third problem is that while the device shows a curved clamping hole appropriate for immovably holding a tublar vessel with the tips contacting one another, the clamping hole is relatively far removed (in comparison with applicant's own invention) from the end of the apparatus, as shown in FIG. 45 of the Sandhaus patent. Use of such a device in a vasectomy procedure, even if for allowing cutting and ligating instead of clipping, would:
require an extraordinarily large incision in the scrotum for insertion of the device, leading to increased likelihood of infection;
cause tissue damage while the device is passed into the scrotum sufficiently far for the clamping hole to engage the vas deferens;
cause tissue damage when the device is closed and clamped around the vas deferens, because tissue behind the vas deferens would necessarily be clamped in addition;
make the vasectomy procedure's lifting and turning of the vas deferens impossible without substantial destruction of surrounding tissue, because of additional tissue caught in the large extension of the forceps' tips beyond the clamping hole; and,
result in additional, unwarranted procedure length, trauma, and danger.
The Sandaus forceps also fails to provide a beveled rim around the edge of the hole nearer its grasping end to provide effective gripping for rotation of a vas deferens or other tubular tissue.
British Patent No. 2,227,200, issued to Malcolm Charles Holbrook, on Jul. 25, 1990, discloses a forceps used for holding a catheter or organ duct during the course of a surgical procedure. This forceps has a three-millimeter clamping hole centered five millimeters from the end of the forceps, a relatively large distance (many times as large as the applicant's own invention) that makes the device unusable for a vasectomy procedure. This forceps was designed for its invisibility to X-rays used during a surgical procedure, and not for use in vasectomies. Use of such a device in a vasectomy procedure, where X-rays are unnecessary, would:
require an extraordinarily large incision in the scrotum for insertion of the device, leading to increased likelihood of infection;
cause tissue damage while the device is passed into the scrotum sufficiently far for the clamping hole to engage the vas deferens;
cause tissue damage when the device is closed and clamped around the vas deferens, because tissue behind the vas deferens would necessarily be clamped in addition;
make the vasectomy procedure's lifting and turning of the vas deferens impossible without substantial destruction of surrounding tissue, because of additional tissue caught in the large extension of the forceps' tips beyond the clamping hole; and,
result in additional, unwarranted procedure length, trauma, and danger.
The Holbrook forceps also lacks a beveled rim around the edge of the hole nearer its grasping end to provide effective gripping for rotation of a vas deferens or other tubular tissue.
The large end design of the Holbrook patent, with its clasping, rather than grasping function, explains why it is in fact not the instrument of choice in performing vasectomies. Instead, surgeons most commonly use the standard or Allis forceps, or the Sandhaus forceps, to perform this procedure. Although vasectomy can be performed with either of these latter two instruments, each presents definite disadvantages, described above, that are resolved by use of the present applicant's invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.